Neural networks supporting autobiographical memory retrieval in posttraumatic stress disorder

Posttraumatic stress disorder (PTSD) affects the functional recruitment and connectivity between neural regions during autobiographical memory (AM) retrieval that overlap with default and control networks. Whether such univariate changes relate to potential differences in the contributions of the large-scale neural networks supporting cognition in PTSD is unknown. In the present functional MRI study, we employed independent-component analysis to examine the influence of the engagement of neural networks during the recall of personal memories in a PTSD group (15 participants) as compared to non-trauma-exposed healthy controls (14 participants). We found that the PTSD group recruited similar neural networks when compared to the controls during AM recall, including default-network subsystems and control networks, but group differences emerged in the spatial and temporal characteristics of these networks. First, we found spatial differences in the contributions of the anterior and posterior midline across the networks, and of the amygdala in particular, for the medial temporal subsystem of the default network. Second, we found temporal differences within the medial prefrontal subsystem of the default network, with less temporal coupling of this network during AM retrieval in PTSD relative to controls. These findings suggest that the spatial and temporal characteristics of the default and control networks potentially differ in a PTSD group versus healthy controls and contribute to altered recall of personal memory.     

Social problem solving and autobiographical memory in posttraumatic stress disorder

This study investigated the relationship between overgeneral autobiographical memory and social problem solving in posttraumatic stress disorder (PTSD). Civilian trauma survivors with and without PTSD (N=41) provided autobiographical memories of events in response to positive and negative cue words. Participants also completed the means-end problem-solving (MEPS) procedure. PTSD participants reported more overgeneral memories, regardless of cue valence, than non-PTSD participants. Individuals with PTSD also displayed poorer problem solving than those without PTSD. Overgeneral autobiographical memory was strongly associated with deficits in problem solving. This study suggests that deficient problem solving in PTSD is associated with impaired retrieval of specific autobiographical memories.     

Autobiographical memory for stressful events: the role of autobiographical memory in posttraumatic stress disorder

To provide the three-way comparisons needed to test existing theories, we compared (1) most-stressful memories to other memories and (2) involuntary to voluntary memories (3) in 75 community dwelling adults with and 42 without a current diagnosis of posttraumatic stress disorder (PTSD). Each rated their three most-stressful, three most-positive, seven most-important and 15 word-cued autobiographical memories, and completed tests of personality and mood. Involuntary memories were then recorded and rated as they occurred for 2 weeks. Standard mechanisms of cognition and affect applied to extreme events accounted for the properties of stressful memories. Involuntary memories had greater emotional intensity than voluntary memories, but were not more frequently related to traumatic events. The emotional intensity, rehearsal, and centrality to the life story of both voluntary and involuntary memories, rather than incoherence of voluntary traumatic memories and enhanced availability of involuntary traumatic memories, were the properties of autobiographical memories associated with PTSD.     

Overgeneral autobiographical memory recollection in Iranian combat veterans with posttraumatic stress disorder

This study examined the recollection of autobiographical material in memory among Iranian military veterans with and without posttraumatic stress disorder (PTSD), and healthy non-trauma-exposed control subjects. Participants completed the Autobiographical Memory Test, Autobiographical Memory Interview (counterbalanced), Impact of Event Scale-Revised, Beck Depression Inventory-II, Wechsler Memory Scale-III and Wechsler Adult Intelligence Scale-Revised. The PTSD group generated fewer specific episodic and semantic details of autobiographical memory compared to the non-PTSD and control groups. Working memory did not significantly moderate the relationship between PTSD diagnosis and reduced autobiographical memory specificity but did moderate the relationship between PTSD diagnosis and semantic recall; semantic memory recall was not significantly related to working memory ability for those with PTSD but was related to working memory ability for trauma survivors without PTSD. While the data provide some support for the expectation that higher working memory ability is associated with an increased ability to retrieve specific memories (i.e. semantic memory recall in those without PTSD), the findings are also consistent with the view that for those with PTSD the demands on working memory required for affect regulation cancel out this influence of working memory in augmenting access to specific memories.     

Impaired autobiographical memory in complicated grief

This study investigated the relationship between autobiographical memory and goals in complicated grief (CG). Twenty-four individuals with CG and 21 bereaved individuals without CG completed an autobiographical memory task and a personal goals task. CG participants were more likely to recall memories related to their loss, particularly in response to negative cues. There was a positive relationship between the proportion of loss-related memories recalled and the proportion of grief-related goals held by individuals after controlling for symptom level. Individuals with CG also showed impaired retrieval of specific autobiographical memories in response to both positive and negative cues. These results suggest that CG is characterised by impaired and biased retrieval of specific autobiographical memories. These patterns are consistent with propositions stemming from the self-memory models of autobiographical memory.     

Maladaptive appraisals as a risk factor for posttraumatic stress: a study of trainee firefighters

This study tested the proposal that catastrophic appraisals are a risk factor for developing stress reactions after trauma. Trainee firefighters (N = 82) were assessed during training (and before trauma exposure), and 68 firefighters were subsequently reassessed 6 months after commencing firefighter duty (after trauma exposure). Initial assessment included the Clinician Administered PTSD Scale, the Traumatic Events Questionnaire, and the Posttraumatic Cognitions Inventory. The Clinician Administered PTSD Scale was again administered approximately 20 months after initial assessment and after trauma exposure. Posttraumatic stress at follow-up was predicted by pre*trauma catastrophic thinking (24% of variance). These findings accord with cognitive models predicting that a tendency to catastrophize about negative events is a risk factor for developing posttraumatic stress symptoms.     

Regret as autobiographical memory

We apply an autobiographical memory framework to the study of regret. Focusing on the distinction between regrets for specific and general events we argue that the temporal profile of regret, usually explained in terms of the action–inaction distinction, is predicted by models of autobiographical memory. In two studies involving participants in their sixties we demonstrate a reminiscence bump for general, but not for specific regrets. Recent regrets were more likely to be specific than general in nature. Coding regrets as actions/inactions revealed that general regrets were significantly more likely to be due to inaction while specific regrets were as likely to be due to action as to inaction. In Study 2 we also generalised all of these findings to a group of participants in their 40s. We re-interpret existing accounts of the temporal profile of regret within the autobiographical memory framework, and outline the practical and theoretical advantages of our memory-based distinction over traditional decision-making approaches to the study of regret.     

Regret as autobiographical memory

We apply an autobiographical memory framework to the study of regret. Focusing on the distinction between regrets for specific and general events we argue that the temporal profile of regret, usually explained in terms of the action–inaction distinction, is predicted by models of autobiographical memory. In two studies involving participants in their sixties we demonstrate a reminiscence bump for general, but not for specific regrets. Recent regrets were more likely to be specific than general in nature. Coding regrets as actions/inactions revealed that general regrets were significantly more likely to be due to inaction while specific regrets were as likely to be due to action as to inaction. In Study 2 we also generalised all of these findings to a group of participants in their 40s. We re-interpret existing accounts of the temporal profile of regret within the autobiographical memory framework, and outline the practical and theoretical advantages of our memory-based distinction over traditional decision-making approaches to the study of regret.     

Assaultive violence and the risk of posttraumatic stress disorder following a subsequent trauma

Breslau, Peterson, and Shultz (2008) reported that prior trauma alone, in the absence of PTSD, did not predict an increased PTSD risk, relative to no prior trauma. Only prior trauma that resulted in PTSD predicted an increased PTSD risk following a subsequent trauma. Recently, Cougle, Resnick, and Kilpatrick (2009) proposed that the effect of prior trauma might vary by type of prior trauma, a possibility not considered in Breslau et al. They report that childhood sexual or physical assault, in the absence of PTSD, increased the PTSD risk following a subsequent trauma. This report examines the PTSD effects of prior assaultive violence, using data from Breslau et al. (1998). The study assessed PTSD in relation to up to three events. Analysis was performed on the subset with PTSD assessment for two distinct events, the earliest trauma and a subsequent trauma (n = 967), using as reference persons with no prior trauma (n = 972). Neither prior assaultive violence nor other prior traumas, in the absence of PTSD, influenced the subsequent risk of PTSD. In contrast, prior PTSD increased considerably the PTSD risk of a subsequent trauma. The limitations in Cougle et al. (2009) and in this study and future research directions are discussed.     

Overgeneral autobiographical memory in adolescents at risk for depression

Autobiographical memory functioning is implicated in the course and onset of depression in adults (Williams et al., 2007), and there is preliminary evidence that adolescents with a diagnosis of depression have a bias towards retrieving overgeneral autobiographical memories (Kuyken & Howell, 2006; Kuyken, Howell, & Dalgleish, 2006; Park, Goodyer, & Teasdale, 2002). In two independent studies we asked whether adolescents at risk for depression exhibit autobiographical memory deficits. In the first community study of 179 adolescents, risk was operationalised as higher scores on neuroticism. We found that neuroticism was associated with greater retrieval of categoric memories to negative cue words and that severity of depressive symptoms mediated this relationship. In the second study, groups of formerly depressed (n=15) and never depressed adolescents (n=15) were matched on age, gender, depressive symptoms and verbal fluency, and again compared on their autobiographical memory functioning. Mirroring the findings from Study 1 we found that risk, operationalised here as a history of depression in remission, was associated with greater retrieval of categoric memories to negative cue words. Taken together, these studies show that risk for depression is associated with a greater tendency to retrieve categoric memories to negative cue words and suggest that autobiographical retrieval may be implicated in onset of depression in adolescence.     

Autobiographical memory in posttraumatic stress disorder before and after treatment

Although overgeneral retrieval of autobiographical memories has been repeatedly demonstrated in posttraumatic stress disorder (PTSD), no studies have indexed overgeneral retrieval before and after treatment of PTSD. Autobiographical memory was assessed in PTSD participants (n=20) prior to commencing cognitive behaviour therapy and 6 months after therapy completion. Fifteen participants completed both assessments. Improvement in PTSD symptoms was significantly associated with improved retrieval of specific memories and decreased retrieval of categoric memories in response to positive cues. These data suggest that symptom reduction during treatment of PTSD leads to greater access to specific memories of positive experiences.     

Reduced autobiographical memory specificity and posttraumatic stress: exploring the contributions of impaired executive control and affect regulation

Reduced specificity of autobiographical memories retrieved to word cues on the Autobiographical Memory Test (AMT) is associated with increased posttraumatic stress in traumatized samples. Theoretical debates concerning the dominant influences on this effect have focused on affect regulation, whereby specific personal information is avoided more by those experiencing greater distress, versus compromised executive control, whereby increased distress is associated with an inability to set aside inappropriately general responses on the AMT. The present study compared these 2 views in a correlational design using a reversed version of the AMT (the AMT-R) for which trauma-exposed participants (N=36) had to generate general memories from the past and avoid specific memories. An emphasis on the role of affect regulation would predict that distress would be associated with reduced specificity (as in the standard AMT), whereas emphasis on the role of executive control would predict that this relationship would be reversed. The data supported the affect regulation account, with greater posttraumatic stress being associated with reduced memory specificity.     

Influence of memory theme and posttraumatic stress disorder on memory specificity in British and Iranian trauma survivors

This study investigated the influence of culture, memory theme and posttraumatic stress disorder (PTSD) on autobiographical memory specificity in Iranian and British trauma survivors. Participants completed the Autobiographical Memory Test and PTSD Diagnostic Scale. The results indicated that the British group provided significantly more personal-themed memories than the Iranian group, while the Iranian group provided significantly more social-themed memories than the British group. The British group also provided a significantly greater proportion of specific personal-themed and social-themed memories than the Iranian group. Overall, in both cultural groups memory specificity was found to be significantly correlated with PTSD symptoms. These findings provide further evidence that regardless of memory theme, specificity of autobiographical memories function to differentiate the self from others and reaffirm the independent self. They also further highlight that pan-culturally an overgeneral retrieval style may be employed by those with PTSD symptoms.     

Memory specificity as a risk factor for suicidality in non-affective psychosis: The ability to recall specific autobiographical memories is related to greater suicidality

A difficulty in recalling specific autobiographical memories has been noted as a risk factor for suicidal behaviour. However, the relationship between memory specificity and suicide has not previously been investigated in those with non-affective psychosis. It was predicted that in this group, more specific memory recall would be associated with an increased risk of suicide. This is because such specific memories are likely to be associated with greater levels of distress and negative affect than less specific memories. This prediction contradicts the prevailing belief that lower memory specificity is associated with greater suicidality. Sixty participants with schizophrenia spectrum disorders were recruited, 40 of whom reported past suicide attempts. Analyses showed suicide attempters recalled a greater proportion of specific memories, whilst controlling for trait anxiety and depressive symptoms. These results supported the main hypothesis, and suggest non-specific memory may have adaptive qualities in individuals with psychosis.     

Specificity of episodic and semantic aspects of autobiographical memory in relation to symptoms of posttraumatic stress disorder (PTSD)

Two studies examined the relationship between the ability to access specific autobiographical material in memory and presence/symptoms of posttraumatic stress. In Study 1, a sample of refugees with a diagnosis of posttraumatic stress disorder (PTSD) completed the Autobiographical Memory Test (AMT) in which they had to generate specific episodic autobiographical memories in response to emotion-related cue words. Results showed that reduced specificity of memories on the AMT was associated with an increased frequency of trauma-related flashbacks but with reduced use of effortful avoidance to deal with trauma-related intrusions in the day-to-day. Study 2 examined retrieval of semantic autobiographical information from previous lifetime periods in groups of cancer survivors with posttraumatic stress and healthy controls. The cancer survivors were able to generate fewer specific semantic details about the personal past compared to the controls. The more symptomatic survivors showed the greatest memory impairment. The data from both studies are discussed in terms of compromised access to specific autobiographical material in distressed trauma survivors reflecting a process of affect regulation.     

Identifying distinct sets of predictors of specific functions of autobiographical memory

ABSTRACT

Grounded in the ecological approach, research has charted several adaptive functions of autobiographical remembering. Each represents a rather different psychosocial domain (i.e., self, social, directive). The goal of this research was to determine the contributions of each of a set of variables, controlling for all others, in predicting use of autobiographical memory to serve each specific function. In two studies, participants (N?=?100; N?=?195) rated frequency of functional use of specific event memories and completed a brief battery of memory-related measures. Most Study One results were replicated in Study Two. Self-relevance of memories was related to their functional use regardless of domain. Each function was also, however, predicted by a unique set of variables consistent with its use in a given psychosocial domain. Findings emphasise how a combination of factors come into play to allow humans to use autobiographical memory to serve various different functions in navigating daily life.     

Gender and posttraumatic stress: sexual violence as an explanation for women's increased risk

Women are approximately twice as likely as men to develop posttraumatic stress disorder (PTSD), but the cause of this disparity remains unclear. This study evaluated 2 alternative explanations of gender differences in PTSD, one pointing to an intrinsic vulnerability in women and the other emphasizing sexual violence across the life span. To test these competing theories, the authors analyzed National Violence Against Women Survey data from 591 victims of partner aggression. Results suggested that gender, when considered alone, has a small but significant effect on PTSD symptom severity. However, once models factor in sexual victimization history, the latter replaces gender as a key determinant of PTSD symptoms. These findings argue against theories of "feminine vulnerability," instead linking PTSD risk to sexually violent situations.     

Hispanic ethnicity and risk for combat-related posttraumatic stress disorder

Hispanic veterans are said to exhibit higher risk of developing posttraumatic stress disorder (PTSD) than veterans of other racial/ethnic backgrounds. This prediction is based largely on findings from the National Vietnam Veterans Readjustment Study (NVVRS; R. A. Kulka et al., 1990a, 1990b). This article first summarizes the findings of the NVVRS with regard to race/ethnicity and PTSD, and then it makes a careful assessment of both the external and the internal validity of these findings. Conceptual issues are addressed and, where possible, further analyses of the NVVRS data set are conducted to identify factors that account for ethnic differences in rates of the disorder. Possible mediators of the effects of Hispanic ethnicity on vulnerability to PTSD are identified, including psychosocial factors (racial/ethnic discrimination and alienation) and sociocultural influences (stoicism and normalization of stress, alexithymia, and fatalism). Areas in which future research is needed are indicated.     

Loneliness as a specific risk factor for depressive symptoms: cross-sectional and longitudinal analyses

The extent to which loneliness is a unique risk factor for depressive symptoms was determined in 2 population-based studies of middle-aged to older adults, and the possible causal influences between loneliness and depressive symptoms were examined longitudinally in the 2nd study. In Study 1, a nationally representative sample of persons aged 54 and older completed a telephone interview as part of a study of health and aging. Higher levels of loneliness were associated with more depressive symptoms, net of the effects of age, gender, ethnicity, education, income, marital status, social support, and perceived stress. In Study 2, detailed measures of loneliness, social support, perceived stress, hostility, and demographic characteristics were collected over a 3-year period from a population-based sample of adults ages 50-67 years from Cook County, Illinois. Loneliness was again associated with more depressive symptoms, net of demographic covariates, marital status, social support, hostility, and perceived stress. Latent variable growth models revealed reciprocal influences over time between loneliness and depressive symptomatology. These data suggest that loneliness and depressive symptomatology can act in a synergistic effect to diminish well-being in middle-aged and older adults.     

Veridical and false memory for scenic material in posttraumatic stress disorder

The question whether memory aberrations in posttraumatic stress disorder (PTSD) also manifest as an increased production of false memories is important for both theoretical and practical reasons, but is yet unsolved. Therefore, for the present study we investigated veridical and false recognition in PTSD with a new scenic variant of the Deese-Roediger-McDermott (DRM) paradigm, which was administered to traumatized individuals with PTSD (n=32), traumatized individuals without PTSD (n=30), and non-traumatized controls (n=30). The PTSD group neither produced higher rates of false memories nor expressed more confidence in errors, but did show inferior memory sensitivity. Whereas depressive symptoms did not correlate with veridical nor false recognition, state dissociation was positively associated with false memories.